This invention relates to the organopolysiloxane compositions for the production of release paper. The compositions have good curability, anti-static properties, oil resistance, and slipperiness, and provide a good releasability (i.e., peelability) to the treated objects.
Conventionally known release papers utilize substrates of a film and sheet type, which are made of celluloses, synthetic resins, and synthetic fibers and with their surfaces coated with releasable silicone. However, these papers tend to be charged by static electricity, especially those with films of polyester and oriented polypropylene (OPP) which are easily charged by friction. This leads to handling problems such as dust adhesion on coated surfaces and blocking between films. When the film with a cured coating is applied to electric parts, it causes trouble such as noise.
Therefore, methods have been proposed to employ undercoating layers which prevent buildup of electrostatic charge on the substrate films and sheets prior to their coating with silicone. Such methods include employing a partially hydrolyzed polysiloxane (Japanese patent application KOKAI (laid open) 61-141553), coating with surfactants, and coating with resin layers which comprise an electroconductive powder such as metals and carbon (Japanese patent application KOKOKU (examined) 62-18448). Further, similar treatments on the back surfaces of these films and sheets are also known.
However, the preparation of silicone coatings which possess an anti-static property by the above methods requires two coating procedures, therefore they are disadvantageous from the viewpoint of production and cost. In addition, the employment of an undercoating layer will negatively affect the curability and adhesiveness of the silicone films which provide releasability.